Annabeth a young girl comes to stay with her very down-to-Earth grandpa, Grandpa Bambertide. Grandpa Bambertide lives in an enormous, wacky house called Gull Cove Cottage located on Gull Cove Beach. Living on this property, Grandpa Bambertide feels that it is his job to take care of, and protect Gull Cove Beach. Something is terribly wrong with the sand on the beach. The sand begins to whisper a song and when the song is over, the sand turns grey and dies. Annabeth and Grandpa Bambertide must get to the bottom of this.
